Add 'tint' (used by Dawn) to Skia's DEPS
Add 'tint' (used by Dawn) to Skia's DEPS

Not used yet (will require some adjustments in Dawn's GN files), but
want to get this in place.

See also: https://skia-review.googlesource.com/c/buildbot/+/347906

Change-Id: I39f632b47a0588c09d17c0f8309158988f061ad2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/348189
Reviewed-by: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Commit-Queue: Brian Osman <794c0b5534edf5601d88e1d41975d0262da12894@google.com>

google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia